1. Field of the Invention
This invention relates to an apparatus for removing a casting from a die casting machine and conveying it to a desired location.
2. Description of the Prior Art
Die casting machines are widely used to produce very smooth, accurate components on a mass production basis. Such a machine supports two die halves, moving one along guide or tie bars into alignment with the other. Pressure is applied to lock and hold the dies together so that no leakage occurs at the seam line, and then molten metal is forced into the die under pressure to form a casting.
For the removal of the casting from the machine and the conveyance thereof to a desired location, industrial robots or similar apparatuses have been used. Such devices include a rod member, a hydraulic cylinder and piston for driving the rod member in reciprocation, and a chuck mechanism connected to one end of the rod member for holding and releasing the casting as desired.
Such a conventional casting removal apparatus employs a rod member driven by only one hydraulic cylinder and piston, whereby its longitudinal dimension is a function of the full rod stroke required for the removal and conveyance of the casting. Consequently, its installation space is relatively large and its floor utility ratio is correspondingly low. Further, it takes a long period of time for the single rod member to travel over its entire stroke for the removal of the casting. This reduces the overall production rate even when a high speed die casting machine(s) is used.
Further, the rod member of the conventional apparatus moves in a horizontal direction to conveniently convey the removed casting to a selected site. This often causes the casting to strike obstacles, such as a core mold assembly, which causes the casting to become flawed or damaged during its removal from the die casting machine. This limits the die casting machine to the production of castings having only a narrow range of shapes, which can be directly removed without blockages.
To prevent the casting from striking obstacles during its removal, means have been provided for moving the gripping mechanism up and down so that the apparatus can move the casting in both the horizontal and vertical directions. This requires either two driving means or a special transmission converting means, however, and both alternatives are complex and costly to manufacture and operate, and are subject to frequent failure and breakdown.
An attempt has been also made to provide a rotating device using a fixed pin in sliding engagement with a spiral groove for turning over the casting held by the gripping mechanism. Such a device can only rotate the casting in one direction, however, and is insufficient for removing a casting which must be rotated in the opposite direction to prevent damage.